On Mon, Jan 26, 2015 at 05:28:42PM +0200, Michael S. Tsirkin wrote: > On Mon, Jan 26, 2015 at 09:37:03AM -0500, Vladislav Yasevich wrote: > > commit 3d0ad09412ffe00c9afa201d01effdb6023d09b4 > > Author: Ben Hutchings <ben@xxxxxxxxxxxxxxx> > > Date: Thu Oct 30 18:27:12 2014 +0000 > > > > drivers/net: Disable UFO through virtio > > > > Turned off UFO support to virtio-net based devices due to issues > > with IPv6 fragment id generation for UFO packets. The issue > > was that IPv6 UFO/GSO implementation expects the fragment id > > to be supplied in skb_shinfo(). However, for packets generated > > by the VMs, the fragment id is not supplied which causes all > > IPv6 fragments to have the id of 0. > > > > The problem is that turning off UFO support on tap/macvtap > > as well as virtio devices caused issues with migrations. > > Migrations would fail when moving a vm from a kernel supporting > > expecting UFO to work to the newer kernels that disabled UFO. > > > > This series provides a partial solution to address the migration > > issue. The series reserves a bit in the skb and sets the bit > > with the ipv6 fragment id has been generated for the packet. > > UFO/GSO code then checks the bit to see if the fragment id > > is already present or if a new fragment id needs to be generated. > > This solution allows host-originated UFO packets to keep a > > better randomized fragment id, as well as generating a randomized > > id for VM generated traffic (solving the fragment id 0 issue). > > > > Vladislav Yasevich (3): > > ipv6: Select fragment id during UFO/GSO segmentation if not set. > > Revert "drivers/net, ipv6: Select IPv6 fragment idents for virtio UFO > > packets" > > Revert "drivers/net: Disable UFO through virtio" > > > > drivers/net/macvtap.c | 16 ++++++++-------- > > drivers/net/tun.c | 25 +++++++++---------------- > > drivers/net/virtio_net.c | 24 ++++++++++-------------- > > include/linux/skbuff.h | 3 ++- > > include/net/ipv6.h | 2 ++ > > net/ipv6/ip6_output.c | 4 ++-- > > net/ipv6/output_core.c | 9 ++++++++- > > net/ipv6/udp_offload.c | 10 +++++++++- > > 8 files changed, 50 insertions(+), 43 deletions(-) > > Should also help a lot to put UDP performance where it was. > > Acked-by: Michael S. Tsirkin <mst@xxxxxxxxxx> > BTW these might also be a good stable candidate. > > > -- > > 1.9.3 _______________________________________________ Virtualization mailing list Virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linuxfoundation.org/mailman/listinfo/virtualization
